:root {
  --blue-color:#3ca9f2;
}
.box {
  /* 让整个内容剧中 */
  display: flex;
  flex-direction: column;
  align-items: center;
}
.cell {
  display: inline-block;
  line-height: 6px;
  width: 5px;
  height: 5px;
  background-color: #2d2f42;
  border-bottom: solid 1px #0f0e18;
  border-right: solid 1px #0f0e18;
  vertical-align: bottom;
  transition: all 400ms ease;
}
#container {
  padding-bottom: 1rem;
  display: flex;
  flex-wrap: wrap;
  width: 601px;
}

.help {
  color: var(--blue-color);
  display: flex;
  justify-content: space-between;
  width: 700px;
  align-items: center;
}

/* 为了更好看，加入了 button 的样式，可有可无！*/
button {
  background: transparent;
  /* border: none; */
  color: var(--blue-color);
  border: 1px solid aqua;
  padding: 0.5rem 1rem;
  cursor: pointer;
  transition: all 400ms ease;
}
button:hover {
  background: var(--blue-color);
  color: #333;
}